a. Field of the Invention
The instant disclosure relates generally to catheters. In particular, the instant disclosure relates to catheters configured to reduce the risk of tissue perforation during diagnostic or therapeutic procedures.
b. Background Art
Electrophysiology catheters are used in a variety of diagnostic and/or therapeutic medical procedures to diagnose and/or correct conditions such as atrial arrhythmias, including for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. Arrhythmias can create a variety of conditions including irregular heart rates, loss of synchronous atrioventricular contractions and stasis of blood flow in a chamber of a heart, which can lead to a variety of symptomatic and asymptomatic ailments and even death.
A medical procedure in which an electrophysiology catheter is used includes a first diagnostic catheter deployed through a patient's vasculature to a patient's heart or a chamber or vein thereof. An electrophysiology catheter that carries one or more electrodes can be used for cardiac mapping or diagnosis, ablation and/or other therapy delivery modes, or both. Once at the intended site, treatment can include, for example, radio frequency (RF) ablation, cryoablation, laser ablation, chemical ablation, high-intensity focused ultrasound-based ablation, and/or microwave ablation. An electrophysiology catheter imparts ablative energy to cardiac tissue to create one or more lesions in the cardiac tissue and oftentimes a contiguous or linear and transmural lesion. This lesion disrupts undesirable cardiac activation pathways and thereby limits, corrals, or prevents errant conduction signals that can form the basis for arrhythmias.
Ablation catheters typically utilize a treatment electrode located at the distal tip of the catheter. The ablation electrode is maneuvered to touch a treatment site prior to the application of ablation energy through the electrode. Since the electrode is on the distal dip of the catheter, there is a localized force concentration where the electrode contacts the target tissue. In some situations, the force concentration at the distal tip can create a risk of perforation of the tissue when ablation energy is being applied. Efforts to lessen the risk of perforation during ablation therapy have included increasing the useable gauge length of the device and by incorporating a thinner material near the distal end of the device.